Tumor Markers

Which of the following tumor markers is correct for the condition?

A) CA (cancer antigen) 27.29 for metastatic cervical cancer
B) CA (cancer antigen) 125 for hepatic carcinoma
C) AFP (α-fetoprotein) for ovarian carcinoma
D) CA (cancer antigen) 19–9 for pancreatic cancer
E) β-hCG (beta unit of human chorionic gonadotropin) for ovarian cancer

Answer:



D) CA (cancer antigen) 19–9 for pancreatic cancer

Discussion:

Recognized tumor markers are most appropriate for monitoring response to therapy and detecting early recurrence.
Cancer antigen (CA) 27.29 is most often used to follow response to therapy in patients with metastatic breast cancer. CA 27.29 is highly associated with breast cancer, although levels are elevated in several other malignancies (colon, gastric, hepatic, lung, pancreatic, ovarian, and prostate cancers). CA 27.29 also can be found in patients with benign disorders of the breast,
liver, and kidney and in patients with ovarian cysts. CA 27.29 levels higher than 100 units per mL are rare in benign conditions.

Carcinoembryonic antigen (CEA) is used to detect relapse of colorectal cancer. CEA elevations also occur with other malignancies.
Nonmalignant conditions associated with elevated CEA levels include cigarette smoking, peptic ulcer disease, inflammatory bowel disease, pancreatitis, hypothyroidism, biliary obstruction, and cirrhosis. Levels exceeding 10 ng per mL are rarely due to benign disease. Fewer than 25% of patients with
disease confined to the colon have an elevated CEA level. Therefore, CEA is not useful in screening for colorectal cancer or in the diagnostic evaluation of an undiagnosed illness. A CEA level should be utilized only after malignancy has been diagnosed.

CA 19–9 may be helpful in diagnosing pancreatic abnormalities. Levels >1,000 units per mL are correlated with pancreatic cancer. Benign conditions such as cirrhosis, cholestasis, cholangitis, and pancreatitis can also result in CA 19–9 elevations, although values are usually <1,000 units per mL.

CA 125 is useful for evaluating pelvic masses in postmenopausal women, monitoring response to therapy in women with ovarian cancer, and detecting recurrence of ovarian carcinoma. Postmenopausal women with asymptomatic palpable pelvic masses and CA 125 levels >65 units per mL likely have ovarian cancer. Because premenopausal women have more benign causes of elevated CA 125 levels, testing for the marker is less useful in this population.

α-Fetoprotein (AFP) is a marker for hepatocellular carcinoma. It is used to screen highly selected populations and to assess hepatic masses in patients at particular risk for developing hepatic malignancy.

Testing for the β-subunit of human chorionic gonadotropin (β-hCG) is an integral part of the diagnosis and management of gestational trophoblastic disease.

Combined AFP and β-hCG testing is an essential adjunct in the evaluation and treatment of nonseminomatous germ cell tumors and in monitoring the response to therapy. AFP and β-hCG are useful in evaluating potential origins of poorly differentiated metastatic cancer.

Prostate-specific antigen (PSA) is used to screen for prostate cancer and detects recurrence of the malignancy.